In order to accurately simulate the dynamic process of soil erosion in the Dongting Lake basin and quantitatively evaluate its contribution of influencing factors, the sediment transport restriction model (TLSD) was coupled on the basis of the Chinese soil erosion equation (CSLE) to realize the analysis of the whole dynamic process of soil separation-transport-sediment, and trend analysis and geographic detector methods were used to explore the spatial and temporal characteristics and influence mechanism of soil erosion in the Dongting Lake Basin from 1980 to 2020. The results showed that:(1) The simulation and measured values of annual sand transport in each hydrological station were well matched by the coupled CSLE-TLSD model (R²=0.56). (2) From 1980 to 2020, the average annual soil erosion modulus of Dongting Lake Basin was 5.09 t/(hm²·a), and both the erosion modulus and area showed a downward trend on the whole. The areas with significant erosion improvement accounted for 22.60% of total basin area, while the area with significant erosion intensification accounted for only 2.69%. (3) With 2005 as the mutation point, the annual total erosion showed a trend of first decreasing and then increasing. (4) Around 2005, the dominant factor leading to soil erosion change changed from land type change to annual rainfall change. In conclusion, soil erosion in the Dongting Lake basin showed a general trend of erosion area shrinkage, while local deterioration trended, among which extreme rainfall events and fruit forest development were the main reasons for the intensification of erosion.